From the Settings app on your iPhone select Mail, Contacts, Calendars
Select Add Account…
Scroll to the bottom and select Other
From the list of calendars select Add Subscribed Calendar
For Server type in www.google.com/calendar/ical/sovrenracing%40gmail.com/public/basic.ics and select Next from the top of the screen. After Verifying you will see the Subscription page. You can change the Description to whatever you want but leave all other fields alone. Select Save and you will now have a subscription in your iPhone calendar to SOVREN Racing.
Note: if you have trouble getting the server above to work try using this one.